Production of porous polyurethane layers

Abstract

The use of particular silicon-containing compounds in the production of porous polyurethane layers for improving the flow properties of the reaction mixture which is reacting to form the polyurethane layer and/or for optimizing the cells of the resulting polyurethane layer, preferably for homogenizing the cell structure over the entire resulting polyurethane layer, especially in the context of artificial leather or foam film production, is described. The silicon-containing compounds have the following formula:

1 . A porous polyurethane layer comprising at least one silicon-containing compound, wherein the silicon-containing compound has the formula (1) 
       
         
           
           
               
               
           
         
         where 
         a is independently from 0 to 500, 
         b is independently from 0 to 60, 
         c is independently from 0 to 10, 
         d is independently from 0 to 10, 
         with the proviso that, for each molecule of the formula (1), the average number Σd of T units and the average number Σc of Q units per molecule is not greater than 50 in either case, the average number Σa of D units per molecule is not greater than 2000 and the average number Σb of the siloxy units bearing R 1  per molecule is not greater than 100, 
         R is independently at least one radical from the group of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated hydrocarbon radicals having from 1 up to 20 carbon atoms, 
         R 2  is independently R 1  or R, 
         R 1  is different from R and R 1  is a radical selected from the group consisting of 
       
       
         
           
           
               
               
           
         
         —CH 2 —CH 2 —CH 2 —O—(CH 2 —CH 2 O) x —(CH 2 —CH(R′)O—) y —R″ 
         —CH 2 —CH 2 —O—(CH 2 —CH 2 O) x —(CH 2 —CH(R′)O—) y —R″ 
         —O—(C 2 H 4 O—) x —(C 3 H 5 O—) y —R′ 
         —CH 2 —R IV    
         —CH 2 —CH 2 —(O) x′ —R IV    
         —CH 2 —CH 2 —CH 2 —O—CH 2 —CH(OH)—CH 2 OH 
       
       
         
           
           
               
               
           
         
         —CH 2 —CH 2 —CH 2 —O—CH 2 —C(CH 2 OH) 2 —CH 2 —CH 3 , 
       
       where 
       x is from 0 to 100, 
       x′ is 0 or 1, 
       y is from 0 to 100, 
       R′ is independently an optionally substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ is independently an substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ substituents may be present within any R 1  radical and/or any molecule of the formula (1), and 
       R″ is independently a hydrogen radical or an alkyl group having from 1 to 4 carbon atoms, a C(O)—R′″ group with R″′=alkyl radical, a —CH 2 —O—R′ group, an alkylaryl group, for example a benzyl group, or a —C(O)NH—R′ group, 
       R IV  is a linear, cyclic or branched, optionally substituted, e.g. substituted by halogens, hydrocarbon radical having from 1 to 50, carbon atoms, 
       R V  —D—G z —
 where D is a linear, cyclic or branched, optionally substituted, e.g. substituted by heteroatoms such as O, N or halogens, saturated or unsaturated hydrocarbon radical having from 2 to 50, carbon atoms, 
 G corresponds to one of the following formulae 
 
       
         
           
           
               
               
           
         
         z can be 0 or 1, 
         where R 1  can also be bridging in the sense that two or three siloxane structures of the formula (1) can be joined via R 1 , in which case R″ or R IV  are correspondingly bifunctional groups, i.e. R V , 
       
       R 4  may independently be R, R 1  and/or a functionalized, organic, saturated or unsaturated radical having substitution by heteroatoms, selected from the group of the alkyl, aryl, chloroalkyl, chloroaryl, fluoroalkyl, cyanoalkyl, acryloyloxyaryl, acryloyloxyalkyl, methacryloyloxyalkyl, methacryloyloxypropyl and vinyl radical, 
       with the proviso that at least one substituent from R 1 , R 2  and R 4  is not R. 
     
     
         2 . The porous polyurethane layer according to  claim 1 , wherein the thickness of the polyurethane layer is in the range from 0.05 to 5 mm. 
     
     
         3 . The porous polyurethane layer according to  claim 1 , wherein the total amount of the silicon-containing compound(s) of the formula (1) used is, based on the finished polyurethane, from 0.01 to 10% by weight. 
     
     
         4 . The porous polyurethane layer according to  claim 1 , wherein a solvent-free or low-solvent process is used for producing the porous polyurethane layer. 
     
     
         5 . The porous polyurethane layer according to  claim 1 , wherein chemically blocked, NCO prepolymers and crosslinkers, comprising aliphatic and/or cycloaliphatic and/or aromatic amines having at least two primary and/or secondary amino groups are used for producing the porous polyurethane layer. 
     
     
         6 . The porous polyurethane layer according to  claim 1 , wherein a polyol component, a catalyst and a polyisocyanate and/or a polyisocyanate prepolymer are used for producing the porous polyurethane layer. 
     
     
         7 . The porous polyurethane layer according to  claim 1  wherein the silicon-containing compound has the formula (1) wherein
 a is from 2 to 150, 
 b is from 1 to 30, 
 c is from 0 to 5, 
 d is from 0 to 5, and 
 R is a methyl radical. 
 
     
     
         8 . A process for producing a composite structure comprising at least one porous polyurethane layer and a support layer, where the at least one porous polyurethane layer is applied directly or indirectly to a support layer and the at least one polyurethane layer is formed by applying a reactive composition capable of forming a polyurethane to the support layer and curing the reactive composition, wherein the formation of the porous polyurethane layer is carried out in the presence of a silicon-containing compound of the formula (1) 
       
         
           
           
               
               
           
         
         where 
         a is independently from 0 to 500, 
         b is independently from 0 to 60, 
         c is independently from 0 to 10, 
         d is independently from 0 to 10, 
         with the proviso that, for each molecule of the formula (1), the average number Σd of T units and the average number Σc of Q units per molecule is not greater than 50 in either case, the average number Σa of D units per molecule is not greater than 2000 and the average number Σb of the siloxy units bearing R 1  per molecule is not greater than 100, 
         R is independently at least one radical from the group of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated hydrocarbon radicals having from 1 up to 20 carbon atoms. 
         R 2  is independently R 1  or R, 
         R 1  is different from R and is independently an organic radial and/or a polyether radical,
 R 1  is a radical selected from the group consisting of 
 
       
       
         
           
           
               
               
           
         
         —CH 2 —CH 2 —CH 2 —O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —R″ 
         —CH 2 —CH 2 —O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —R″ 
         —O—(C 2 H 4 O—) x —(C 3 H 5 O—) y —R′ 
         —CH 2 —R IV    
         —CH 2 —CH 2 —(O) x′ —R IV    
         —CH 2 —CH 2 —CH 2 —O—CH 2 —CH(OH)—CH 2 OH 
       
       
         
           
           
               
               
           
         
         —CH 2 —CH 2 —CH 2 —O—CH 2 —C(CH 2 OH) 2 —CH 2 —CH 3 , 
       
       where 
       x is from 0 to 100, 
       x′ is 0 or 1, 
       y is from 0 to 100, 
       R′ is independently an optionally substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ is independently an optionally substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ substituents may be present within any R 1  radical and/or any molecule of the formula (1), and 
       R″ is independently a hydrogen radical or an alkyl group having from 1 to 4 carbon atoms, a C(O)—R′″ group with R″′=alkyl radical, a —CH 2 —O—R′ group, an alkylaryl group, for example a benzyl group, or a —C(O)NH—R′ group, 
       R IV  is a linear, cyclic or branched, optionally substituted, e.g. substituted by halogens, hydrocarbon radical having from 1 to 50 carbon atoms, 
       R V  —D—G z —
 where D is a linear, cyclic or branched, optionally substituted, e.g. substituted by heteroatoms such as O, N or halogens, saturated or unsaturated hydrocarbon radical having from 2 to 50 carbon atoms, 
 G corresponds to one of the following formulae 
 
       
         
           
           
               
               
           
         
         z can be 0 or 1, 
         where R 1  can also be bridging in the sense that two or three siloxane structures of the formula (1) can be joined via R 1 , in which case R″ or R IV  are correspondingly bifunctional groups, i.e. R V , 
       
       R 4  may independently be R, R 1  and/or a functionalized, organic, saturated or unsaturated radical having substitution by heteroatoms, selected from the group of the alkyl, aryl, chloroalkyl, chloroaryl, fluoroalkyl, cyanoalkyl, acryloyloxyaryl, acryloyloxyalkyl, methacryloyloxyalkyl, methacryloyloxypropyl and vinyl radical,
 with the proviso that at least one substituent from R 1 , R 2  and R 4  is not R. 
 
     
     
         9 . The process for producing a composite structure according to  claim 8 , wherein the reactive composition capable of forming a polyurethane comprises chemically blocked, NCO prepolymers and crosslinkers, comprising aliphatic and/or cycloaliphatic and/or aromatic amines having at least two primary and/or secondary amino groups. 
     
     
         10 . The process for producing a composite structure according to  claim 8 , wherein the reactive composition capable of forming a polyurethane comprises
 i) a polyol having primary and/or secondary terminal hydroxy functions,   ii) a polyisocyanate and/or a polyisocyanate prepolymer, and   iii) a catalyst.   
     
     
         11 . The composite structure comprising at least one porous polyurethane layer according to  claim 7  and a support layer, wherein the two layers are joined indirectly or directly to one another. 
     
     
         12 . The composite structure obtainable by the process according to  claim 8 . 
     
     
         13 . An artificial leather comprising the composite structure according to  claim 11 . 
     
     
         14 . A foam film comprising the composite structure according to  claim 11 . 
     
     
         15 . The porous polyurethane layer according to  claim 1 , wherein the thickness of the polyurethane layer is in the range from 0.15 to 1 mm. 
     
     
         16 . The porous polyurethane layer according to  claim 1 , wherein the total amount of the silicon-containing compound(s) of the formula (1) used is, based on the finished polyurethane, from 0.1 to 3% by weight. 
     
     
         17 . The porous polyurethane layer according to  claim 1 , wherein chemically blocked, NCO prepolymers and crosslinkers, comprise aliphatic and/or cycloaliphatic and/or aromatic amines having at least two primary and/or secondary amino groups are used for producing the porous polyurethane layer. 
     
     
         18 . The process for producing a composite structure according to  claim 8 , wherein the reactive composition capable of forming a polyurethane comprises oxime-blocked, NCO prepolymers and crosslinkers, comprising aliphatic and/or cycloaliphatic and/or aromatic amines having at least two primary and/or secondary amino groups. 
     
     
         19 . The porous polyurethane layer according to  claim 1  wherein the silicon-containing compound has the formula (1) wherein
 R 1  is different from R and is independently an organic radial and/or a polyether radical,
 R 1  is a radical selected from the group consisting of 
 
 
       
         
           
           
               
               
           
         
         —CH 2 —CH 2 —CH 2 —O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —R″ 
         —CH 2 —CH 2 —O—(CH 2 —CH 2 O—) x —(CH 2 —CH(R′)O—) y —R″ 
         —O—(C 2 H 4 O—) x —(C 3 H 5 O—) y —R′ 
         —CH 2 —R IV    
         —CH 2 —CH 2 —(O) x′ —R IV    
         —CH 2 —CH 2 —CH 2 —O—CH 2 —CH(OH)—CH 2 OH 
       
       
         
           
           
               
               
           
         
         where 
         x is from 1 to 50, 
         x′ is 0 or 1, 
         y is from 1 to 50, 
         R′ is independently an optionally substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ is independently an optionally substituted alkyl or aryl group having from 1 to 12 carbon atoms, substituted, for example, by alkyl radicals, aryl radicals or haloalkyl or haloaryl radicals, where different R′ substituents may be present within any R 1  radical and/or any molecule of the formula (1), and 
         R″ is independently a hydrogen radical or an alkyl group having from 1 to 4 carbon atoms, a C(O)—R′″ group with R″′=alkyl radical, a —CH 2 —O—R′ group, an alkylaryl group, for example a benzyl group, or a —C(O)NH—R′ group, 
         R IV  is a linear, cyclic or branched, optionally substituted, e.g. substituted by halogens, hydrocarbon radical having from 13 to 37 carbon atoms, 
         R V  —D—G z —
 where D is a linear, cyclic or branched, optionally substituted, e.g. substituted by heteroatoms such as O, N or halogens, saturated or unsaturated hydrocarbon radical having from 4 to 37, carbon atoms, 
 G corresponds to one of the following formulae 
 
       
       
         
           
           
               
               
           
         
         z can be 0 or 1, 
         where R 1  can also be bridging in the sense that two or three siloxane structures of the formula (1) can be joined via R 1 , in which case R″ or R IV  are correspondingly bifunctional groups, i.e. R V , 
       
       R 4  may independently be R, R 1  and/or a functionalized, organic, saturated or unsaturated radical having substitution by heteroatoms, selected from the group of the alkyl, aryl, chloroalkyl, chloroaryl, fluoroalkyl, cyanoalkyl, acryloyloxyaryl, acryloyloxyalkyl, methacryloyloxyalkyl, methacryloyloxypropyl and vinyl radical,
 with the proviso that at least one substituent from R 1 , R 2  and R 4  is not R. 
 
     
     
         20 . The porous polyurethane layer according to  claim 2  wherein the silicon-containing compound has the formula (1).